This invention relates broadly to a lower torso exercise machine for performing leg exercises while in a seated position. More particularly, the invention pertains to a seated assembly for such a leg, exercise machine which is adjustable to properly support the upper legs of the user during leg extensions and leg curls.
Combination leg extension/leg curl machines have been built for many years. As with most combination weight training machines, there is some compromise in the function of one exercise, or both, to make the machine work in both functions. In the case of the leg extension/curl, the first problem is with the pivot point. Because the mechanics of doing a leg extension forces the knee down, the pivot point of the machine has to be lower in relationship to the seat cushion than when doing a seated leg curl which tends to raise the knee. The second problem is that the seat cushion must support the entire upper leg while doing leg extensions. If the seat pad extends under the lower portion of the upper leg during seated leg curls, it restrict the ability to flex the hamstring muscles completely.
One known combination exercise machine is disclosed in U.S. Pat. No. 5,980,434, issued Nov. 9, 1999 to Webber. In this patent, a free swinging roller pad assembly is adjustably mounted on a frame and movable between a down position, in which the roller pad assembly engages behind a user""s knees for providing a support surface during leg extensions, and a raised portion in which the roller pad assembly engages a user""s thighs for providing a bearing surface and resisting raising of the user""s legs during leg curls. Webber""s exercise apparatus includes a seat which is non-adjustable between leg extensions and leg curls. In the ""434 patent, the plane of the seat passes substantially directly through the pivot access of the roller pad assembly in performing both leg curls and leg extensions. As a result, there is no differential between the plane of the seat cushion and the pivot axis which detracts from the proper form of the desired leg exercise.
It would be desirable to provide a combination leg exercise machine, wherein an exerciser""s legs are supported in a judicious manner, such that the pivot point of the machine is lower relative to the plane of the seat cushion and the leg extension exercise than when performing a leg curl. Such relationship compensates for the tendency of the exerciser""s knees to be forced downwardly in a leg extension exercise and the inclination of the exerciser""s knees to be forced upwardly in a leg curl exercise. It is also desirable to provide a leg extension/leg curl exercise machine wherein the entire upper leg is supported by the seat cushion during leg extensions. It is further desirable that the seat cushion does not extend entirely along the exerciser""s upper leg during leg curls because it restricts the ability to flex the hamstring muscles completely.
It is one object of the present invention to provide a combination leg exercise machine for enabling an exerciser to perform leg extensions and leg curls in a seated position.
It is also an object of the present invention to provide a leg extension and leg curl machine having an adjustable seat assembly constructed and arranged so that the plane of the seat bottom passes below the pivot axis of a pivotable leg engaging cushion assembly.
It is a further object of the present invention to provide a lower limb exercise machine wherein the seat assembly selectively places an exerciser in one predefined position to optimally perform leg extensions and another predefined position to optimally perform leg curls.
It is another object of the present invention to provide a multi-exercise machine for legs, in which a seat assembly is adjustable back and forth on a frame, such that the vertical distance between the pivot axis of a leg engaging cushion assembly and the plane of the seat bottom when performing leg extensions is less than the vertical distance between the pivot access and the plane of the seat bottom performing leg curls.
In one aspect of the invention, a leg exercise machine has a support frame, a seat assembly including a seat bottom disposed upon a mounting framework secured on the frame for performing leg exercises in the form of leg extensions and leg curls. A resistance structure provides resistance to the leg exercises performed on the machine. A first roller cushion assembly is pivotably connected to the frame about a first pivot axis, is coupled to the resistance structure and is adapted to be engaged by an exerciser""s legs. A second roller cushion assembly is pivotably secured to the frame about a second pivot axis and is adapted to be engaged with an exerciser""s thighs when performing leg curls. The invention is improved wherein at least a portion of the seat assembly is adjustable relative to the frame, such that the vertical distance between the pivot axis and the plane of the seat bottom when performing leg extensions is less than the vertical distance between the pivot axis and the plane of the seat bottom when performing leg curls. The support frame has a pair of tubular support members supporting a pair of aligned pillow block bearings for receiving a shaft defining the first pivot axis. The first roller cushion assembly includes a telescopic arm having a sleeve mounted for rotation on a shaft. A cam is rotatably mounted on the shaft, and is formed with a double-lobe construction. The support frame supports a weight stack, as well as a pulley arrangement on which a drive belt is entrained. One end of the drive belt is fixed to the cam, and the other end of the drive belt is attached to the weight stack. The cam is provided with a first exercise selector arrangement for moving a first roller cushion between a leg extension mode and a leg curl mode. The second roller cushion assembly includes a second exercise selector arrangement for moving a second roller cushion between a first position adapted to engage the thighs of an exerciser and a second position adapted to be spaced away from the thighs of the exerciser. The seat assembly includes a pair of spaced apart base frames joined together at one end by a stop tube having a pair of stop pads projecting therefrom. The seat assembly further includes a generally T-shaped mounting frame upon which a seat bottom is secured. The seat bottom and mounting frame are constructed and arranged to be shifted between a forward position corresponding to a leg extension position, and a rearward position corresponding to a leg curl position by means of a forward pivot link and a rearward pivot link. The mounting frame has a pair of downwardly depending stop pins which are alternately engageable with the stop tube or stop pads. The drive belt is wrapped around one lobe of the cam during leg extensions and wrapped around the other lobe during leg curls. The knees of the exerciser are adapted to flex in the vicinity of the first pivot axis. The rotational range of the second lower cushion assembly is limited by engagement of a tab with a stop pin provided on an L-shaped tube supported on the frame.
In another aspect of the invention, a leg extension and leg curl exercise machine includes a support frame, a seat assembly including a cushioned seat bottom mounted on the frame for performing leg extension and leg curl exercises in a seated position and a resistance structure for providing resistance to the leg extensions and leg curls performed on the machine. A lower roller cushion assembly is pivotally connected to the frame about a first pivot axis in front of the seat assembly and coupled to the resistance structure for providing resistance to leg extensions and leg curls in both forward and rearward pivot directions. The lower roller cushion assembly is adapted to be engaged with an exerciser""s legs while seated on the seat assembly to perform leg extensions and leg curls. An upper roller cushion assembly is pivotally secured to the frame about a second pivot axis and is movable between a raised position spaced above an exerciser""s thighs during leg extensions and a lowered position against the top of an exerciser""s thighs during leg curls. With this construction, the seat bottom is adjustable between a leg extension position such that the plane of the seat bottom is located below the first pivot axis and a leg curl position located downwardly and rearwardly of the leg extension position.
Various other objects, features and advantages of the invention will be made apparent from the following description taken together with the drawings.